Bomb fuze



FIG. 1.

Sept. 23, 1958 Filed Jan. 27, 1953 R. BIANCHI ETAL BOMB FUZE 2 Sheets-Sheet 1 INVENTORS ALBERT S. WILL RENATO BIANCHI ATTORNEYS- 2 Sheets-Sheet 2 INVENTORS ALBERT S. WILL RENATO BIANCHI fflwflw 19m. #Hok L ATTORNEYS R. BIANCHI ETAL BOMB FUZE Sept. 23, 1958 Filed Jan. 27, 195 3 mm mm mm .u \"T HIW WM mm United States Patent BOMB FUZE Renato Bianchi, Laurel, and Albert 8. Will, University Park, Md., assignors to the United Statesof America as represented by the Secretary ofthe Navy Application January 27, 1953, Serial No. 333,625

6 Claims. (Cl. IM -70.2)

(Granted under-Title 35,- .Ut S. Code (1952), see. 266) The invention described herein maybe manufactured and used by or for the Government ofthe United States of America for governmental purposes withoutthe payment of any royalties thereon ortherefor.

The present invention relates to a bomb f-uze and more particularly to a new and improved electrically controlled base-and. nose fuze for use with afire bomb.

Heretofore, fire bombs employed mechanically actuated fuzes wherein means controlled by the rotation of an impeller released the arming means for movement to an armed position when the impeller has made a predetermined number of. revolutions duringthe free flight of the bomb. toward a target after being released from'jan' aircraft in flight. It has been. found, however, that impeller type arming devices have not proven'ent'irel'y satisfactory. When the bombis. l'au'nchedl'from a high-speed aircraftthe' impeller. cannot Withstand the high pressure to which. it is subjected during" air. travel thereofandtas the bomb is released from the. highespieed aircrafttoward atarget.

The. present invention contemplates the provision of a new andimprove'd electric fuze arrangement for a fire bomb wherein means controlled by an electrical impulse causes the fuze to be armed in predetermined time delayed relation with respect to the release of the bomb from an aircraft in flight,.and in which means are provided for" charging a storage device as the bomb is released from the aircraft whereupon the energy. may be instantaneously discharged through an electroresponsive detonator upon impact of the bomb'with' a target thereby to cause fragmentation of the bomb casing and thus scatter the 'ignited incendiary 'rnixture'over a large target area;

An object of the presentinventio'n isto provide'a new andimproved electric fuze arrangementfor" use in a fire bomb;

Another object'of thepresent invention'isthe provision of a fuze' device for a fire bomb wherein an explosive element fired in response to an electrical impulse received thereby actuates the fuze to an armed"positiongintime delayed relation with respect to therelease of thebomb from an aircraft in flight.

Another object of the invention is the provision'of an electricfu'ze for a fire bomb wherein means 'areprovided forstepping up andstoring'electrical energy as the bomb is'released from an aircraft in flight.

A" further object of theinvention is thepr'ovision'of a" newand'improved' electric fuze for a fire bomb" wherein a fusible element is employed to isolate a charged capacitor from the charging means when the'charge on the capacitorhas reached a-predeterminedvalue and'in which means are provided for discharging the energy'insta'n taneously from the capacitor through an electroresponsive detonator'upon impact of'the bomb'with a target.

A. still further'object of the'inv'entionis the provision of an electric fuze wherein a capacitor is charged through a'fusible'element at a rate insuflicient to'cause fusing of the element, the element "being adapted "to' fuse when the 2,853,0lfi Patented Sept. 23, 1958 2 charge on the condenser has reached a predetermined value.

An additional object resides in the provision of an elecr tric fuze for an ordnance missile wherein means are provided for delaying the arming of the fuze for a predetermined period of time after the missile has been released from an aircraft in flight.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following description when considered in connection with the ac companying drawings wherein: a

Fig. 1 is a schematic view of the fuze arrangement of the present invention illustrating a preferred embodiment thereof in connection with a fire bomb and a portion of an aircraft to which the bomb is releasably connected;

Fig. 2 is a diagrammatic representation of the electric fuze arrangement of the device of Fig. l; and

Fig. 3 is a diagrammatic representation of analternate arrangement of the device of Fig. 2.

Referring now to the accompanying drawings wherein like reference characters designate like parts throughout the several views and more particularly to Fig. 1 thereof the numeral 10 generally indicates a fire bomb comprising a casing 11. The bomb 10 is a conventional type fire bomb and is adapted to be providedwith the usual incendiary mixturesuch, for example, as gasoline gel or the like. These bombs have been effectively used against personnel, wooden piers, infiammable'stores and the like since they burst upon impact and scatter the flamingmixtu're over a large area.

The bomb 10 is releasably'supported on the bomb rack 12 by the conventional release means indicated by the numeral 13 whereupon the bomb may be released at will from an aircraft in flight toward a target by the bombardier, the bomb rack 12 being preferably mounted on the wing 14 of the aircraft. 1

The present invention relates to an" electrical fuze arrangement particularly adapted to initiate the aforesaid pyrotechnicmaterial arranged within the fire bomb therebyto' fire the bomb on impact with the target. The arrangementcomprises' a pair of fuzes 15'16 which are identical in construction, fuze 15 being disposed within theno'se' of thebomb and fuze 16 beingdisposed within the" tail of the bomb. As'shown' on Fig. l the fuzes 15 a'nd 16:.areelectrically connected to a switch device genera'lly indicated by the numeral 17 by a pair of cables 18 -19, theswitchbeing disposed within a well or recess 21 formed in the casing 11 and secured thereto in any suitable manner. A breakaway plug 22 is operatively connected to the switch 17 and to a suitable source of electricalenergy [not shown] such, for example as a battery or thelike, the source of electrical eiiergy being carried bythe aircraft. From the foregoing, it will be understoodthat the breakaway plug 22 andlswitch 17 provide means whereby electrical energy may be transferred from thesource of power arranged within'theaireraft'to the fuzes 15 -46 whereupon the fuzes are adapted to be actuated from an initial safeposition to an armed position in time delayed relation with respect to the release of the bomb from an aircraft in flight. The operation'of the aforesaid fuze arrangement will be more'clea'rly apparent with-reference to the circuit arrangement of Fig. 2 in connection with the following detailed description thereof.

If'will be noted that the breakaway plug 22 comprises apair of slip connectors 2324, connected to the aforesaid'source of electrical energy [not shown] by a pair of conductors 2526, the slip connectors being'of any con ve'n'tional type and adapted to provide means whereby the fuzes 15-16 may be electrically connected to a suitable source of electrical energy as the bomb is placed in the bomb rack; One terminal of the source of power is grounded as at 27 by way of conductor 25 and slip connector 23, the other terminal thereof being connected to a switch element 28 having a pair of mutually spaced wiper elements 29-31.

The fuzes and 16 are adapted to be actuated by an electrical impulse from the source of power as the wiper 29 momentarily engages the pair of contacts 32 of fuze 16 and the wiper 31 momentarily engages the pair of contacts 33 of fuze 15. It will be understood that the breakaway plug is secured to the aircraft and is adapted to be disconnected from the switch 17 when the bomb has traveled a predetermined distance from the aircraft after being released therefrom. Furthermore, the switch 17 is secured to the bomb and the moveable switch element 28 thereof is "connected to the breakaway plug. By the aforesaid arrangement it will be understood that the switch element 28 is moved sufficiently to cause the wipers 29-31 to be moved into and out of engagement with the stationary contacts 32-33 respectively before the breakaway plug becomes detached from the switch 17. The breakaway plug is constructed and arranged in such a manner as to insure operation of the switch 17 before the breakaway plug is detached therefrom.

As clearly shown on Fig. 2 each of the fuzes 15-16 are identical in construction and each fuze is provided with a fusible element 34, pyrotechnic delay element 35, storage device 36, arming switch 37, arming rotor 38, primer 39, and an impact switch 42.

Conductor 43 of the tail fuze 16 is connected to one of the contacts 32 while the other conductor 43 is connected to one of the contacts 33. Conductors 43 are also connected to the pyrotechnic delay elements 35 and conductors 44 are connected to the other one of the contacts 32 and 33 respectively and to the aforesaid storage devices 36 by way of conductors 45 and 44. It will be noted that the fusible elements are disposed between the storage devices 36 and the source of electrical energy. By this arrangement a firing circuit for the pyrotechnic elements 35 and a charging circuit for the storage devices 36 is established as the switch element 28 is actuated and the wipers 29-31 engage contacts 32-33. When this occurs the pyrotechnic elements 35 are fired in response to an electrical impulse received from the source of electrical energy and the storage devices 36 are also charged to approximately 28 volts thereby. It will be understood that the fusible elements are constructed in such a manner as to allow charging of the condensers 36 before being fused bythe energy passing therethrough through aforesaid switches 42 and 47. Furthermore, switches 48 and contacts 52 interrupt the firing circuit to the primers 39 and switches 49 and contacts 53 maintain the primers '39 shorted. It will be understood that the firing circuits to the primers remain interrupted and the primers remain shorted until the switches 37 are moved from the initial position to a moved position. However, when switches 37 are actuated in the aforesaid manner the primers 39 are unshorted and connected in series with the impact switches 42 and the charged condensers 36 by reason of the movement of switches 47 and 49 from an initial closed to an open position and movement of switches 48 from an initial open position to a closed position and thus the firing circuit from the condensers 36 to the primers 39 are established by way of conductors 55 and 56. The energy stored in condensers 36 will not be discharged therefrom through the primers 39, howfrom the source of electrical energy. When this occurs the condensers 36 are isolated from the contacts 32 and 33. It will be noted that the arming switches 37 of Fig. 2 are provided with actuating members 46 operatively connected to the delay elements 35 and having a plurality of switch elements 47, 48 and 49 secured thereto respectively and adapted tobe actuated from an initial safe position to a moved position as the members 46 are moved a predetermined amount by the delay element as the delay elements are fired, the switches being actuated to the aforesaid moved position substantially 1.5 seconds after the initial firing impulse received thereby. Furthermore, if desired, the actuating members 46 may be connected to the arming rotors 38 which may be provided with out of line explosive trains adapted to be aligned with the primers 39 as the actuating members are moved by the delay element.

It will be noted on Fig. 2 that switch elements 47 are normally in engagement with contacts 51, switch elements 48 are normally out of engagement with contacts 52 and switch elements 49 are normally in engagement with contacts 53. 'By this arrangement the condensers 36 are connected in series with impact switches 42 and switch elements 47 and thus should the impact switches 42 be moved to a closed position prior to the expiration of the aforesaid time delay period and before movement of the switches 37, the condensers 36 will be discharged ever, until the impact switches 42 are actuated to a closed position in response to impact of the bomb with a target. When this occurs the energy in the aforesaid condensers 36 are discharged through the primers 39 and thus the primers are fired in response thereto. The flashes from the primers 39 fire the explosive trains arranged within the arming rotors 38 and initiates the conventional pyrotechnic elements associated with the fire bomb whereupon fragmentation of the casing 11 occurs and the ignited incendiary mixture is scattered over the target area.

With reference to Fig. 3'it will be noted that the circuit arrangement thereof is similar to the arrangement of Fig. 1 but in lieu of the fusible elements 34-34, the fuzes 58-59 of Fig. 3 are each provided with a cold cathode diode 61 and a transformer 62. Furthermore, the explosive delay devices 35 are each provided with a resistor 63 which is in parallel with the bridge elements of the conventional squibs arranged within each of the delay devices. It will be-understood that by the use of the resistors 63 in the aforesaid manner an electrical path between the source of power and the transformers will be established by way of the resistors should for any reason the aforesaid bridge elements fuse orburn prematurely and thus a pulse of adequate duration will be transmitted to the transformers. a

In' the arrangement of Fig. 3 it will be understood that the electrical energy is supplied to the aforesaid fuzes 58-59 from the source of electrical energy [not shown] by switch arrangement 60 when the pair of contact elements 64-65 are moved into engagement with contacts 66-67 thereof. By this arrangement the condensers 36 are charged through transformers 62, the transformers being adapted to step up the voltage sufficiently to cause break down of the cold cathode diodes 61 and building up of the charge on the storage condensers 36. Whencondensers 36 are charged, the diodes 61 cease to conduct and the condensers 36 are isolated from the switch arrangement 60 and the charge will remain on. the condensers 36 until switches 42 are actuated in response to impact of the bomb with the target. Since the discharge cycle and firing cycle of the device of Fig. 3 is the same as shown and described in connection with Fig. 1 further detailed description thereof is deemed unnecessary.

From the foregoing, it will be apparent that a new and improved electric fuze has been devised for use in a fire bomb wherein means controlled by an electrical impulse causes the fuze to be armed in predetermined time delayed relation with respect to release of the bomb from an aircraft in flight, and in which means are provided for charging a storage device as the bomb is released from the aircraft whereupon the energy may be instantaneously discharged through an electroresponsive detonator upon impact of the bomb with the target thereby to cause fragmentation of the bomb casing and thus scatter the ignited incendiary mixture over'a large target area.

Obviously many modifications and variations of the present invention are possible in thelight of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed as new and desired to be secured by Letters Patent in the United States is:

1. "In an electric bomb fuze of the character disclosed, the combination of a source of electrical energy, an electroresponsive detonator, storage means, means including an electrical circuit for discharging energy from said source to said storage means, means for interrupting said circuit when the charge on said storage means has reached a predetermined value, means including an electroresponsive explosive device connected to said source of energy for arming the fuze, and means for discharging said storage means through the detonator upon impact of the bomb with a target thereby to fire the detonator and explode the bomb.

2. In an electric bomb fuze of the character disclosed, the combination of a source of electrical energy, an electroresponsive detonator, storage means, means including an electrical circuit for transferring said energy from said source to the storage means, means included in said circuit and rendered effective when the charge on said storage means has reached a predetermined value for inter rupting said circuit and maintaining a charge on the storage means, means including an explosive device connected to said source of energy for arming the fuze in response to an electrical impulse, and impact responsive means connected to said storage device for discharging said energy through the detonator upon impact of the bomb with a target thereby to fire the detonator and explode the bomb.

3. An electric fuze of the character disclosed for use in a fire bomb comprising, in combination, a source of electrical energy, a storage device, means including an electrical circuit for transferring said energy from the source to said storage device, means included in said circuit and rendered effective when the charge on the storage device has reached a predetermined value for interrupting said circuit and maintaining a charge on the storage means, a normally interrupted firing circuit, a normally open switch means for rendering said firing circuit effective as the switch is actuated to a closed position, an explosive device connected to said source of electrical energy and included in said electrical circuit for moving said switch to said closed position, an electroresponsive detonator connected in said firing circuit for electrical communication with said storage device when said switch has been actuated to said closed position, and impact responsive means connected to said storage device for discharging said energy through the detonator upon impact of the bomb with a target thereby to fire the detonator and explode the bomb.

4. In an electric fuze for arming an airborne fire bomb in time delayed relation with respect to the release of the bomb from the aircraft holding means, the combination of a source of electrical energy arranged in the aircraft, storage means in said bomb, means including an electrical circuit for discharging energy from said source to said storage means, means for interrupting said circuit when the charge on said storage means has reached a predetermined value thereby to maintain said charge on the storage means, means including an explosive device actuated in response to an electrical impulse for arming the fuze in time delayed relation with respect to the release of the bomb by said holding means, means for connecting the storage means and the explosive device to said source of energy as the bomb is released from said holding means, and means for discharging said storage means through the detonator upon impact of the bomb with a target thereby to fire the detonator and explode the bomb.

5. In an electric fuze for arming an airborne fire bomb in time delayed relation with respect to the release of the bomb from the aircraft holding means, the combination of a source of electrical energy in the aircraft, storage means in said bomb, circuit means connected to said storage means for discharging energy from said source of energy to the storage means, means for detachably connecting said circuit means to the source of energy,

means included in the circuit and responsive to a predeterimned voltage for interrupting said circuit when the charge on the storage means has reached a predetermined value thereby to maintain said storage means charged to said predetermined value, a normally interrupted firing circuit, a switch device included in said firing circuit, means no said switch device for rendering said firing circuit effective when the switch device is actuated, explosive means operatively connected to said switch device for actuating said switch device in response to an electrical impulse received thereby, and impact responsive means included in said firing circuit for discharging said energy through the detonator upon impact of the bomb with a target thereby to fire the detonator and explode the bomb.

6. In a bomb adapted to be released from an aircraft having a source of electrical potential, a fuze comprising an electro-responsive detonator, an electric storage device, circuit means including a-step up voltage transformer for transferring potential from said source to said storage device, a cold cathode diode included in said circuit for interrupting said circuit when said storage device has been charged to a predetermined potential level, an electroresponsive explosive device connected to said source for arming the fuze in response to an electrical impulse, and means for discharging said storage device through said detonator upon impact of the bomb with a target thereby to fire the detonator and explode the bomb.

References Cited in the file of this patent FOREIGN PATENTS 

